Sharif Digital Repository

This paper is concentrated on soot formation in a JP combustor and it studies the emission in its exhaust gases when the combustor is equipped with different types of exhaust swirler. So, to approve the developed solver, it is required to predict one related flame structure accurately right at the first step. In this regard, we solve a well-documented benchmark test case with available data from experiment. These data are then compared with the current numerical results to evaluate the discrepancies. The comparison indicates that there is good agreement between them. Afterwards, we equip a similar combustor with different types of swirler, simulate the new designed combustor configurations,... 

This paper is concentrated on soot formation in a JP combustor and it studies the emission in its exhaust gases when the combustor is equipped with different types of exhaust swirler. So, to approve the developed solver, it is required to predict one related flame structure accurately right at the first step. In this regard, we solve a well-documented benchmark test case with available data from experiment. These data are then compared with the current numerical results to evaluate the discrepancies. The comparison indicates that there is good agreement between them. Afterwards, we equip a similar combustor with different types of swirler, simulate the new designed combustor configurations,... 

This paper concerns an understanding of thrust vectoring, in the presence of co-flowing secondary air. An experimental and computational study was performed on a circular-shape nozzle, integrated with a Coanda surface, to investigate the feasibility of multi-directional deflection of the engine exhaust gases. The vectoring angle was controlled by the relative blowing momentum of air that was injected tangentially through the slots, surrounding the main nozzle. A state of the art design that uses a small step, just after the main nozzle to turn the flow into eddy, was also employed to enhance the effectiveness of the method. The secondary section was divided into four identical sections for... 

The feasibility of using fluidic thrust-vectoring system, as a control technique for the longitudinal and lateral trim purpose was investigated in this study. For this purpose, integration of a Co-flow method into the propulsion unit of a conceptual aerial vehicle was assumed. The focus of the research presented was to estimate the required thrust vector angle in order to trim the aerial vehicle in different flight phases. Since the fluidic thrust vectoring requires secondary air flow to deflect the engine exhaust gas, this research also provides an analytical toolset for preliminary sizing of a suitable secondary air supply. It was found that thrust vectoring could be an effective mean of... 

In this work, we numerically study the effect of a mini-scale primary-air injector on the formation of soot nano-particles in a model tubular-type gas-turbine combustor fed with JP, i.e. gaseous JP-1. We solve a documented experimental (benchmark) test case to evaluate our numerical solution and compare the achieved flame structure with that of the measured and reported data. The obtained numerical results show good agreements with the experimental data. After ensuring the validity of numerical tool, we install a mini-scale injector, split the incoming air-flow between the primary and secondary streams, inject the primary air into the combustor via the mini-scale injector, and compare the... 

In this study, a jet propulsion JP combustor is studied numerically to investigate the combustor wall temperature influences on the soot characteristics emitted at its exhaust. There are a number of ways to control the combustor wall temperatures benefiting from different wall cooling technologies. Irrespective of using different high technology cooling systems, it is important to recognize how the wall temperature can affect the soot emission from one specific JP engine. Before examining the main combustor, it is important to assess the accuracy of the computational fluids dynamics (CFD) tool via solving a benchmark problem. In this regard, the predicted flame structure for the benchmark... 

Micro gas turbines are considered to meet the electrical, domestic hot water, heating and cooling energy needs of a residential building located in Tehran, Ahvaz and Hamedan. The building is 10 stories high and has a total of 8000 m2 floor area with the peak demands of electricity of 32.96 kW, DHW of 0.926 kW, heating load of 1590 kW and the cooling load of 2028 kW, when the building is located in Tehran. With these demands, 30 micro turbines of 30 kW (nominal power) are needed to meet all the energy needs of the building. The excess electricity generated by the micro turbines is to be used in a heat pump, and the energy in the exhaust gases is to be used to meet other thermal energy needs... 

In this article, an attempt is made to utilize the exhaust gases of a small gas turbine to augment power output through the employment of a thermoacoustic system. A simple gas turbine cycle is selected as the base cycle and it is assumed that the thermoacoustic system is powered only by the waste heat of the base gas turbine. A comprehensive cycle analysis of the integrated gas turbine thermoacoustic engine (IGTTE) is carried out from an energy and exergy point of view. Exergy efficiency and internal exergy efficiency are calculated for the different components of the base gas turbine engine as well as the IGTTE. Value and exergy flow diagrams are used to investigate the possible... 

Feeding a laboratory furnace with the gaseous kerosene, the resulting two-phase turbulent flame is simulated to study the effects of injecting soot nano-particles into the inflow air on the emissions of smoke aerosol, CO, and CO2species pollutants, and the resulting radiation heat transfer. We use our past experiences in aerosol modeling of soot nano/micro particles in turbulent nonpremixed flames burning simple hydrocarbon fuels and extend them to study the effects of injecting gaseous kerosene on the aforementioned parameters. To model the evolutionary process of soot nanoparticle formation, i.e., the nucleation, coagulation, surface growth, and oxidation, we employ a two-equation soot... 

The aim of this study is to couple molten carbonate fuel cell (MCFC) stack with integrated gasification combined cycle fed by refinery residues, to remove CO2 from gas turbine exhaust gases that have CO2 emission rate of 14,200 ton/year. By applying multi-objective optimisation (MOO) using genetic algorithm, the optimal values of operating load and the corresponding values of objective functions are obtained. The MOO of the MCFC system regarding two scenarios is performed. The first scenario is minimisation of cost of electricity (COE) and CO2 emission rate. Objective functions of the second scenario are the same as in the first scenario while CO2 tax is taken into account. Results show that...